1. Field of the Invention
The present invention relates to a photographing device provided with a polarizing filter that is rotatable about an optical axis of a photographing optical system in an optical path thereof, and also relates to a method of controlling the rotational angle position of such a polarizing filter.
2. Description of the Related Art
According to the related art, there is a photographing device provided with a polarizing filter, and a method of controlling the rotational-angle position of the polarizing filter, in which a rotational angle position of the polarizing filter is controlled on the basis of an object luminance signal. The object luminance signal is captured by preliminary rotation (scanning) of the polarizing filter.
However, the object luminance signal not only includes a pure polarization effect via the polarization filter, the object luminance signal is also affected by disturbance (noise) that is caused by variation of brightness of object image. In particular, if a blinking object (such as traffic signal, turn-signal lamp of vehicle, blinking neon sign, etc.) exists in the object image, such a blinking object considerably increases the adverse influence of problematic disturbance in the object luminance signal, so that a precise control of the rotational-angle position of the polarizing filter cannot be achieved. In other words, such a change in the object luminance signal due to a blinking object is erroneously determined as being caused by the polarization effect of the polarizing filter.
In the related art, a photographing device and a control method thereof is disclosed in Japanese unexamined patent publication 2006-208714.